Ground deformation study of M-w 7.7 Bhuj earthquake of 2001

A preliminary study of ground deformation of the catastrophic Bhuj earthqua ke of 26 January 2001 is described. This earthquake of magnitude M-w 7.7, M s 8 caused large-scale destruction including 20,000 deaths. Surface faultin g has not been detected probably due to the 23 km focal depth. Reverse faul ting is inferred along a steeply, dipping fault that could be the westward extension of the northern boundary fault of the Wagad uplift. If extended u pward it would meet the surface 25 kin north of the Kutch Mainland Fault. A s a result of this uplift, intense land deformations have been observed in a 40 km x 20 km area like lateral spreading, ground uplifts (about a meter at Budharmora extending for 300 in in length), ground slumping (at Chobari and Amarsar), and deep and wide cracks (N-S at Manfara but mainly E-W at ot her places). A NNW-trending 5-km long fracture bem,een Manfara and Kharoi, interpreted as a right lateral strike slip fault by some could be a tension al fracture. Similar is a small fracture at Sikra. Strong shaking has cause d liquefaction with ejection of a lot of water and some sand in Banni grass land, in saline areas of Great Rann and Little Rann of Kutch and in coastal areas tip to 200 kin distance from the epicenter Stray incidences of lique faction have occurred up to 275 km such as south of Ahmedabad and near Jamb usar.